Management of occlusion, which is one theme in the long-term dental care of children, must consider development of oral function. We investigated the occlusal force of caries-resistant children with normal occlusion using occlusal indicating wax, and followed their development. The occlusal force increased with age, as the thickness of the wax after occlusion decreased.
     These findings suggest that occlusion of deciduous dentition changes over time. Without proper management, even normal, caries-free children may develop unstable occlusion.

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     We compared the oral distribution and pathogenic characteristics of two homology groups in Prevotella intermedia. Almost all of the strains presumptively identified by indole production and enzyme patterns belonged to the ATCC25611 or 33563 groups of Prevotella intermedia. Bacterial strains of the 33563 group predominated in cases of periapical periodontitis, cellulitis and oral microbial flora. Both groups occurred at about the same frequency for bacteria from periodontal pockets. Fifty percent of the patients and volunteers had both of the homology groups. These results indicated that both groups are prevalent in the oral cavity.
     Thirty-seven strains of the 25611 group and 113 strains of the 33563 group were examined by electron microscopy and were classified into six types based on morphologically distinct surface appendages, designated as A, AL, E, F, G and H. Type A, AL and H appendages were present on both groups. However, type E, F and G appendages were associated exclusively with the 33563 group, suggesting that the two groups have different adherent characteristics. Both produced β-lactamase, DNase, lipase, lecithinase, hyaluronidase, chondroitin sulfatase, collagenase or a viscous material and both expressed one to six kinds of hydrolytic enzymes and/or viscous material.
     Therefore, both groups of the Prevotella intermedia may contribute to exacerbation of oral infections.

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     We recently isolated a few anaerobic gram-negative, black-pigmented rods from saliva and periapical lesions. Several of these isolates, although resembling Prevotella melaninogenica, P. denticola or P. loescheii in most of their phenotypic expression, were capable of producing indole, a biochemical characteristic atypical of the P. melaninogenica group.
     Enzyme patterns by the API ZYM system and protein bands on SDS-PAGE gels were useful in differentiating the above three Prevotella species from other black-pigmented Prevotella, and in differentiating P. loescheii from P. melaninogenica and P. denticola. We failed to find phenotypic characteristics for differentiating P. melaninogenica and P. denticola. DNA-DNA hybridization is thus necessary for identification of the two Prevotella species.

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     A long-term study on soft tissue healing to acid-treated root surfaces in monkeys and dogs carricd out. The experimental teeth including gingiva and bone were extracted at 2, 3 and 4 weeks after surgery, and undecalcified specimens were prepared for transmission electron microscopy. In dogs, complete interdigitation was seen between exposed and newly-formed fibrils two weeks after surgery. In monkeys, however, inflammatory cells were identifiable in the wound even at three weeks, and weak interdigitation occurred as late as four weeks. The results showed profound differences between monkeys and dogs in the response of healing tissue to exposed fibrils.

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     We identified fimbriae-positive streptococci isolated from buccal mucosa, supragingival plaque and saliva, and examined their distribution and adherence properties. Of 349 strains isolated, 119 possessed peritrichous fimbriae or fimbrial tufts projecting from streptococcal cell surfaces. Based on biochemical characteristics and DNA-DNA hybridization, all strains tested were identified as either S. salivarius or S. oralis. S. salivarius cells were abundant in supragingival plaque and saliva, while S. oralis cells were predominant in buccal mucosa. As a result, all strains of S. salivarius possessed peritrichous fimbriae, while fimbrial tufts were present on 50% of S. oralis. S. salivarius were more hydrophobic (an average of 28.6%), followed by type D of S. oralis (43.0%) and type A of S. oralis (68.4%). S. salivarius had more capacity to adhere to human buccal epithelial cells and to form in vitro plaque than S. oralis. Moreover, hydrophobicity and the ability to adhere to epithelial cells of S. salivarius with short fimbriae, designated as type Aa, differed from S. salivarius with long fimbriae, designated as type Ab. These results indicate that there are several adhesins on the fimbriae of S. salivarius and S. oralis, and that S. salivarius have more pathogenic potential than S. oralis.

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We evaluated the growth characteristics of cells derived from the bone side (BP cells), middle (MP cells) and cementum side (CP cells) of the human periodontal ligament (PL). The PL cells were cultured from the mandibular right third molar and first premolar. Cultured cells were grown in Dulbecco's modified Eagle medium containing various concentrations (5, 10 and 20%) of fetal bovine serum (FBS), and the number of cells was counted at 5 and 10 days. The growth of the CP cells was the lowest of all examined. The BP, MP and CP cells showed different growth patterns for each of the three FBS concentrations. These results suggested that different areas of the PL have different proliferative responses.

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Glycosaminoglycans (GAGs) are covalently attached to core protein, forming glycoconjugates called proteoglycans which play an important role in the expression of cellular function. We studied the structure of GAGs in healthy and diseased oral tissues by HPLC. The GAG content in both inflamed human gingiva and human gingival crevicular fluid with Periodontal disease was greater than that in healthy controls. The molecular weight of synovial fluid hyaluronic acid in the human temporomandibular joint tended to decrease with osteoarthritis, along with increases in N-acetyl-β-glucosaminidase activity. The GAG content in the rat articular disk tended to decrease with age. These results indicate that qualitative and quantitative changes in oral tissue GAG are associated with the health of the tissue, and suggest that GAG analyses may be useful in diagnosing oral diseases.

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This study was designed to examine whether or not gingival fibroblasts attach to curetted cementum surfaces in periodontally-involved human teeth. Only the superficial surface of the cementum was removed from five periodontally-involved human teeth, using approximately 20 strokes of a curette. No root treatment was performed on five others. Root slices were placed in 35 mm culture dishes, and human gingival fibroblasts (HGF) were seeded in each dish. The specimens were processed for transmission electron microscopy after four weeks. Although HGF failed to attach to the cemental surfaces, they attached to the curetted cementum, and synthesized new fibrillar materials. These results demonstrated that curetting the cementum surface facilitates cell attachment on the entire area corresponding to the periodontal pocket.

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Although the effects of prostaglandin E_1 (PGE_1), a potent vasodilator on cerebral Vasculature have been reported, there have been no reports of its effects on cerebrospinal fluid (CSF) dynamics. I determined the rate of CSF formation (Vf), CSF pressure (CSFP), sagittal sinus pressure (SSP), carotid blood flow (CaBF), and regional cerebral blood flow (r-CBF) in anesthetized cats during and after decrease of arterial pressure induced by intravenous PGE_1. There were no significant changes in Vf, CSFP, or SSP during deliberate hypotension with PGE_1. Regardless of decreases in CaBF, r-CBF was maintained during hypotension. These findings indicated that PGE_1 does not significantly effect intracranial pressure dynamics, and therefore can be recommended for induction of deliberate hypotension under general anesthesia.

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